Many control apparatuses for controlling access to memory devices, such as hard disk drive (HDD), have a function for monitoring occurrence of an error in access to the memory device and a function for recording such occurrence as an error score according to the type of the error. When the error score reaches a certain value, these control apparatuses determine that malfunction has occurred in the memory device, and take a measure such as disconnecting the memory device.
Also, the next storage system is proposed as an example of a storage system having a function for monitoring a failure that might occur in the memory device. In this storage system, a connection control unit connects a communication control unit with a plurality of storage devices by means of a switch. The connection control unit transmits error information to the communication control unit upon recognizing a failure in access to a storage device, and decides whether the communication control unit is to execute a failure recovery process on the basis of the error information.
Also, the next disk array is proposed, for example. In this example, a disk device including a disk array has a function for collecting and retaining its operation history information, as well as a function for transferring the operation history information to a higher-level control apparatus in response to a transfer request from the higher-level control apparatus.
See, for example, Japanese Laid-open Patent Publication Nos. 2007-141185 and 6-51915.
In recent years, storage systems tend to include an increasing number of control apparatuses for controlling access to memory devices, so as to enlarge the scale of the storage system. Also, there is a need for diversifying access routes and access control systems in addition to the scale enlargement, and for example it is considered that a certain control apparatus accesses a memory device via another control apparatus. In this configuration, it is possible that an error in access to one memory device is detected by all control apparatuses. In this case, if each individual control apparatus detects failures of memory devices, the failures are unable to be detected with respect to each memory device.
Also, when memory devices accessed from a plurality of control apparatuses are managed by one control apparatus, there is a problem that a processing load of the control apparatus for managing the memory devices increases, affecting the primary process of the control apparatus, i.e., controlling access to the memory devices.